In Major League Baseball, the designated hitter is a hitter who does not play a position, but instead fills in the batting order for the pitcher. The DH may only be used for the pitcher (and not any other position player), as stated in Rule 6.10. Use of the DH is optional, but must be determined prior to the start of the game. If a team does not begin a game with a DH, the pitcher (or a pinch-hitter) must bat for the entire game.

The designated hitter may be replaced as DH only by a player who has not entered the game. If a pinch hitter bats for, or a pinch runner runs for, the DH, that pinch-hitter or pinch-runner becomes the DH.

The designated hitter can be moved to a fielding position during the game. If the DH is moved to another position, his team forfeits the role of the designated hitter, and the pitcher or another player (the latter possible only in case of a multiple substitution) would bat in the spot of the position player replaced by the former DH. If the designated hitter is moved to pitcher, any subsequent pitcher (or pinch-hitter thereof) would bat should that spot in the batting order come up again (except for a further multiple substitution.) Likewise, if a pinch-hitter bats for a non-pitcher, and then remains in the game as the pitcher, the team would forfeit the use of the DH for the remainder of the game, and the player who was DH would become a position player.

Unlike other positions, the DH is "locked" into the batting order. No multiple substitution may be made to alter the batting rotation of the DH. In other words, a double switch involving the DH and a position player is not legal. For example, if the DH is batting fourth and the catcher is batting eighth, the manager cannot replace both players so as to have the new catcher bat fourth and the new DH bat eighth. Once a team loses its DH under any of the scenarios discussed in the previous paragraph, the double switch becomes fully available, and may well be used via necessity, should the former DH be replaced in the lineup.

In Major League Baseball, during interleague play, the application of the DH rule is determined by the identity of the home team, with the rules of the home team's league applying to both teams. If the game is played in an American League park, the designated hitter is in effect; in a National League park, the pitcher must bat or else be replaced with a pinch-hitter. On June 12, 1997, San Francisco Giants outfielder Glenallen Hill became the first National League player to DH in a regular-season game, when the Giants met the American League's Texas Rangers at The Ballpark in Arlington in interleague play.[2]

At first, the DH rule was not applied to the World Series. From 1973 to 1975, all World Series games were played under National League rules, with no DH and pitchers batting. For 1976, it was decided the DH rule would apply to all games in a Series, regardless of venue, but only in even-numbered years. Cincinnati Reds first baseman Dan Driessen became the first National League player to act as a DH in any capacity (regular season or postseason) when he was listed as the DH in the first game (he was the DH in all four Series games that year). This practice lasted through 1985. Beginning in 1986, the DH rule was used in games played in the stadium of the American League representative.

There was initially no DH in the All-Star Game. Beginning in 1989, the rule was applied only to games played in American League stadiums.[3] During this era, if the All-Star Game was scheduled for an American League stadium, fans would vote in the DH for the American League's starting lineup, while the National League's manager decided that league's starting DH. Since 2010, the designated hitter has always been used by both teams regardless of where the game is played.[4]

In spring training games, the home team chooses whether the designated hitter is used. Occasionally National League teams opt to use the designated hitter, usually when a player is recovering from an injury.

In practice, it is very rare for a team to forfeit its right to a DH, even by substitution. The following are known instances in regular season games (not counting interleague play) of an American League pitcher coming to bat:

Up 10-1 in the 8th inning of a game played on September 3, 1973, the Milwaukee Brewers elected to send DH Bobby Mitchell into left field, thereby forfeiting their right to use a DH. Relief pitcher Eduardo Rodríguez accordingly came to bat in the ninth—and hit an RBI triple, sealing the Brewers' 13-5 win over Cleveland.[9]

In a 3-3 tie in the 8th, on a game played on June 12, 1974, the Milwaukee Brewers moved DH Tim Johnson to SS for defensive insurance, giving up their DH in the process. Reliever Tom Murphy then pitched into the 13th inning, hitting a single in his two at-bats. He lost the game, however, in the 13th, as the Kansas City Royals emerged 4-3 victors.[10] Oddly, Murphy picked up the relief effort from Eduardo Rodriguez, the most recent AL relief pitcher to get a hit in a game.

In the midst of an 18-8 loss to Kansas City on August 29, 1979, the Milwaukee Brewers made several position changes, willingly losing their DH in the process. Amongst other moves, 3B Sal Bando was moved to pitcher in the 4th inning—he hurled three innings, going to bat in the fifth as a pitcher and popping up. In the 7th, Bando and 2B Jim Gantner switched positions, though while a pitcher Gantner never made it to the plate as a batter. The next inning, Buck Martinez (normally a catcher) entered the game as the Brewers sixth pitcher of the day. As a pitcher, Martinez batted in the 9th, stroking an RBI single. For each of Bando, Gantner and Martinez, all of whom played in over 1,000 ML games, this game was their lone appearance in the majors as a pitcher.[12]

In his first of three major league pitching appearances for the Toronto Blue Jays, Bob Bailor, normally a position player, was moved from shortstop to pitcher in the 7th inning in a game on August 4, 1980, replacing Tom Buskey (who had been ejected from the game for throwing at a batter). Simultaneously, Garth Iorg moved from third to shortstop, and Steve Braun was inserted at third, replacing DH Otto Vélez in the lineup. This meant that the Jays lost their DH. Bailor finished out the game as a pitcher, and came to bat in the ninth and popped out.[13]

On September 26, 1987, Detroit Tigers designated hitter Darrell Evans moved to first base in the bottom of the seventh inning in a game against the Toronto Blue Jays, causing pitcher Mike Henneman to be inserted into the first baseman's spot in the batting order. Henneman batted for himself in the ninth, but struck out attempting to bunt. The Blue Jays scored three runs in the bottom of the ninth to win the game 10–9 in the midst of a pennant race, with Henneman taking the loss.[14]

The Seattle Mariners' Brian Holman was in the midst of a perfect game bid against Oakland on April 20, 1990, when Pete O'Brien was moved from DH to 1B in the eighth inning. Seattle therefore lost their DH and Holman batted for himself in the ninth, reaching base on an error by the second baseman. Holman subsequently lost his perfect game bid with two out in the bottom of the ninth, when pinch hitter Ken Phelps hit a home run. Holman retired the next batter to end the game, winning 6-1.[15]

Leading 11-1 in the 7th inning of a game played on August 2, 1991, the Texas Rangers made a plethora of defensive changes—including moving DH Geno Petralli to 3B, thereby losing their DH. This allowed reliever Mike Jeffcoat to come to bat in the ninth. Jeffcoat hit an RBI double, and later came around to score the Rangers' 15th and final run in a 15-1 pasting of the Milwaukee Brewers.[17]

On July 29, 1995, down by two runs in the bottom of the 8th inning, Kansas City Royals manager Bob Boone made several substitutions in an ultimately successful attempt to tie up a game against the Detroit Tigers. During the inning, DH Joe Vitiello hit an RBI single to right field to pull the Royals within one run. Boone pinch ran for Vitiello with utility infielder Chris Stynes and pinch hit for starting second baseman David Howard with outfielder Chris James. James singled to center, and Boone used two more pinch hitters in the following at bat before the game was ultimately tied later in the inning. Having used all of his reserve middle infielders, Boone chose to play Stynes at second base in the top of the ninth, thereby forfeiting the DH. Before Jon Nunnally homered to score the next run and win the game in the bottom of the 16th inning, Royals relief pitcher Hipolito Pichardo pitched five innings and had to bat twice. He went 0-2 with a line out to first and a ground out to shortstop before picking up the victory in the game.[18]

On May 23, 1996, the Boston Red Sox elected to lose their DH in the late innings, sending DH Jose Canseco out to play left field with a 9-4 lead in the 8th. Sox starter Roger Clemens hit for himself in the bottom of the 8th inning, and singled. The Red Sox won the game 11-4.[19]

Attempting to hold on to a 6-5 lead on June 9, 1996, the California Angels made some defensive changes in the bottom of the 9th, including moving DH Rex Hudler to 2B. Reliever Troy Percival, however, blew the save and allowed the Cleveland Indians to tie the score, and the game went into extra innings. Percival batted for himself in the 10th and struck out. Later, pitcher Ryan Hancock came into the game, and hit for himself in the 13th. Hancock singled and came around to score the go-ahead run in what turned out to be an 8-6 victory for the Angels.[20]

On August 16, 1997, in the 8th inning of a 5-5 tie against the New York Yankees, the Texas Rangers made several defensive changes, including moving DH Iván Rodríguez to catcher, thereby losing their DH. Texas Rangers reliever John Wetteland consequently batted for himself in the 10th inning—and hit an RBI double in an 8-5 Rangers win.[21]

An unusual instance of an American League team forfeiting its right to the DH happened on July 22, 1999 to the Cleveland Indians in a game against the Toronto Blue Jays. Manny Ramirez, the designated hitter, accidentally went into right field in the top of the 2nd instead of Alex Ramirez, causing some confusion. The Indians lost their DH, Alex Ramirez was out of the lineup, and Charles Nagy was forced to hit in Alex Ramirez's place going 0 for 2. John McDonald later pinch-hit for Nagy in the 6th inning.[22]

On August 10, 1999, the Tampa Bay Devil Rays brought in third baseman Wade Boggs to pitch against the Baltimore Orioles in a blowout in favor of Baltimore. Boggs, peculiarly, was put into the DH's place in the lineup at the same time he was being brought into the game to pitch. Pitcher Boggs grounded out in his only at bat.[23]

In a game played on July 31, 2000, Boston Red Sox DH Darren Lewis was moved to CF in the 8th inning, and the Red Sox consequently lost their ability to use a DH. Pitcher Hipolito Pichardo batted for himself in the 9th, striking out.[24]

In the second game of a doubleheader between the Minnesota Twins and Chicago White Sox on July 6, 2007, the Twins initially used their starting catcher, Joe Mauer, as the DH because Mauer had started the first game at catcher. The starting catcher for the second game, Mike Redmond, however, was forced to leave the game in the first inning due to injury after accidentally being struck in the head by the bat of Jim Thome, and Mauer had to take the field as the replacement catcher. Twins starting pitcher Matt Garza thus was forced into the batting order and became the first American League pitcher to bat in a regular-season American League game since Hipolito Pichardo on July 31, 2000. Garza went 0-for-2, but picked up the win in a 12-0 victory over the White Sox.[25][26]

On May 19, 2008, the Minnesota Twins surrendered their DH position in a game vs. the Texas Rangers in Minneapolis. Twins Manager Ron Gardenhire had to use rookie pitcher Bobby Korecky as a hitter in the 11th inning of the game; Korecky had only pitched in five major league games prior to this and had never had a major league at-bat. Nevertheless, Korecky hit the first pitch he saw into right field for a single, becoming the first Twins pitcher to get a hit in an American League game since the implementation of the DH rule. The inning ended with Korecky stranded at 3rd base with the bases loaded. Korecky ended up getting his first major league win in this game as the Twins won 7–6 in 12 innings.[27]

On May 17, 2009, Tampa Bay Rays manager Joe Maddon incorrectly listed both Ben Zobrist and Evan Longoria as third basemen in the starting lineup against the Cleveland Indians. Maddon's intent was for Zobrist to play at third and Longoria to be the DH. In the middle of the first inning, Cleveland manager Eric Wedge brought Maddon's error to the umpires' attention, and the Rays were forced to forfeit their DH, remove Longoria from the lineup since Zobrist played the top half of the first inning at third base (Longoria was available as a substitute since he never appeared in the game before that point), and bat starting pitcher Andy Sonnanstine at Longoria's place in the order—third. This was the first time a pitcher was in the initial batting order in a game between two American League teams since Ken Brett in 1976. Sonnanstine went 1 for 3 with an RBI double, and picked up the win in a 7-5 Tampa Bay victory.[28]

On June 11, 2011, Toronto Blue Jays second baseman Mike McCoy was moved from second base to pitcher in the top of the ninth, as the Jays were losing a 16-4 rout against the Boston Red Sox. Rather than use a bench player at second base, third-baseman Jayson Nix moved to second base and DH Edwin Encarnación was inserted at third base. McCoy pitched a three-up, three-down ninth, and then batting as a pitcher, ground out in the bottom of the inning.[29]

On May 6, 2012, with the game tied in the 16th inning and with only starters in the bullpen, the Baltimore Orioles elected to use DH Chris Davis as a pitcher against the Boston Red Sox, thus forfeiting their right to a DH. Davis made it through the inning with no runs and the game continued with a tied score into the 17th. At this point, also out of relief pitchers, Boston activated DH Darnell McDonald as pitcher. (McDonald had entered the game in the eighth inning to pinch run for starting DH David Ortiz.) McDonald surrendered three earned runs before the inning ended on a ground out by Davis, in his only at-bat as a pitcher (he would finish the game 0-for-8 with five strikeouts).[31] As Boston was the home team and trailing, Davis was forced to return to pitch the second half of the 17th inning. Davis allowed no runs before McDonald (in his only at-bat as a pitcher) grounded into a double play, ending the inning and the game. Because the game was tied when both DHs were activated, they were both listed as the pitchers of record; Davis was credited with the win and McDonald with the loss.[32]

In the midst of a 16-0 blow-out on July 25, 2012, Toronto Blue Jays catcher Jeff Mathis was moved to pitcher in the top of the 9th. He gave up the Oakland A's 15th and 16th runs of the day, then led off the bottom of the ninth with a line-drive single.[33]

On August 3, 2012, Toronto Blue Jays first baseman Yan Gomes was moved to the outfield after center fielder Colby Rasmus suffered an injury in the top of the 12th against the Oakland Athletics. With no bench players available, designated hitter Edwin Encarnación replaced Gomes at first. Toronto relief pitcher Aaron Loup, who eventually picked up the loss, would enter the game in the bottom of the 13th and bat lead off in place of Rasmus two innings later, grounding out to short. Loup's at bat was trumpeted as the first by a Blue Jays pitcher in an American League game in team history, although technically it was only the first at bat by a Blue Jays player whose primary role on the team was as a pitcher: As mentioned above, Bob Bailor had batted as a pitcher in 1980, Mike McCoy did it in 2011, and Jeff Mathis had come to the plate as a pitcher for the Jays just 8 days earlier, but all of these players were primarily position players who had been called in to pitch.[34][35]

On September 4, 2012, down 18-8 to the Minnesota Twins in the ninth, the Chicago White Sox elected to bring left fielder Dewayne Wise into pitch the ninth inning, and to move DH Hector Gimenez into left field, thereby losing their DH. Wise pitched a scoreless top of the ninth, then, batting as a pitcher in the bottom of the inning, stroked an RBI double for the ninth and final ChiSox run of the game.[36]

On September 13, 2012, in Baltimore, Tampa Bay Rays manager Joe Maddon moved DH Evan Longoria to third base as a defensive substitution in the ninth inning of a tied game. After a series of pinch-hitters in the pitcher's spot, relief pitcher Chris Archer eventually came to bat in the fourteenth. Remarkably, this was Archer's second at-bat of the contest; he had entered the game in the 10th inning as a pinch-hitter for injured second baseman Ryan Roberts. Archer struck out both times (although the first strikeout was charged to Roberts, because Archer had inherited a two-strike count).

On April 27, 2013, the Baltimore Orioles pitcher Chris Tillman batted for himself in a game against the Oakland A's. This was because starting catcher Taylor Teagarden had left the game due to injury, being replaced by Matt Wieters, who had started the game at DH. Tillman batted and struck out in the seventh inning, and was replaced by a reliever anyway before the next inning - manager Buck Showalter's rationale was that with no one on base and two men out (the circumstances at the time of Tillman's plate appearance) it did not make sense to use a pinch-hitter who could instead be used in a higher-leverage situation later in the game. Later in the game, the pitcher's spot came up again, with Darren O'Day the putative hitter, but Nolan Reimold pinch-hit for him.

Two days later on April 29, 2013, in a game against the Los Angeles Angels of Anaheim, Oakland Athletics centerfielder Chris Young suffered a quadriceps injury after batting in the bottom of the 15th inning. In the top of the 16th, with no remaining position players on the team's bench, the A's repositioned left fielder Yoenis Cespedes to center field and moved designated hitter Seth Smith to left field, thus sacrificing the designated hitter spot. Pitcher Jerry Blevins would later relieve Brett Anderson and strike out in his 18th-inning at bat.

On June 4, 2013, in a blowout loss to the Boston Red Sox, designated hitter Lance Berkman was removed from the game and was replaced by third-baseman Geovany Soto in the bottom of the eighth inning, when the Rangers were trailing by a score of 17-5. Thus, David Murphy, an outfielder who filled in as a pitcher in the bottom of the eighth (and was the only Ranger pitcher to throw a scoreless inning), had to hit in the top of the ninth inning. He flew out to center.

On June 22, 2014, due to catcher Derek Norris getting injured from a Jonathan Herrera backswing, a flurry of defensive changes in the top of the 10th inning for the Oakland Athletics in a game against the Boston Red Sox included designated hitter Josh Donaldson taking the field at third base. The pitcher's spot was then due up third in the bottom of the 10th. Fernando Abad was the pitcher of record (and wound up taking the loss as the Red Sox won 7-6 in 10), but he did not bat – fellow reliever Sean Doolittle took the plate appearance and grounded out to first to end the game.

Down 15-0 to the Texas Rangers on August 5, 2014, the Chicago White Sox had Adam Dunn, who began the game at DH, take the mound in the top of the ninth. He then batted as the pitcher in the bottom half, grounding out to second.

In the following instances, a team forfeited their right to a DH, but due to pinch-hitters or other factors, a pitcher did not actually end up making a plate appearance:

On September 5, 1976, New York Yankees starting pitcher Catfish Hunter pinch-hit for second baseman Sandy Alomar, Sr. in top of the 6th inning and stayed in the lineup as the pitcher for the Yankees in the bottom half of the inning. César Tovar, the one-time designated hitter in the game, then took over at second base.[38] (Note: There is now a section of the rule that states that the game pitcher may only pinch-hit for the designated hitter; therefore, this move would now be prohibited.)

During the month of September, 1980, Baltimore Orioles manager Earl Weaver inserted a pitcher into the DH slot but would use a hitting specialist (such as Benny Ayala or Terry Crowley) to pinch-hit when the designated hitter's first turn came up. There was a game on September 17, 1980, during which the Orioles and the Detroit Tigers both used the short-lived strategy.[39] (Note: Due to the loophole of which Earl Weaver took advantage, there was a rule change shortly thereafter that states the DH must come to bat at least once, unless the opposing team changes pitchers.)

In the bottom of the eighth on July 15, 1993, the Seattle Mariners' Jeff Nelson was moved from the pitcher position to left field. The strategy allowed Nelson to stay in the game while left-handed pitcher Dennis Powell came in to pitch to Mike Greenwell in a game at Boston. By moving the pitcher into a defensive position, Nelson was put into the designated hitter's spot in the batting order while the new pitcher (Powell) was placed into the left fielder's place in the batting order. (It is very uncommon to see this particular move in an American League ballgame due to the DH.) Powell's turn in the batting order came up in the top of the ninth: Pete O'Brien pinch hit for him. Left fielder Nelson was then moved back to pitcher, and pitched in the bottom of the ninth.[40]

On May 20, 1996 in the ninth inning of a game between the Red Sox and the Oakland A's, the Red Sox, leading 16-4, moved Mike Stanley from DH to catcher, forfeiting the DH. Alex Delgado replaced Bill Haselman, who had been the catcher, in the lineup, and was placed at third base. Tim Naehring, who had started the game third base, moved to second base, and Brent Knackert, who was entering the game as the pitcher, replaced outgoing second baseman Wil Cordero in the lineup batting first. Knackert pitched a scoreless 9th and consequently did not have to take his turn at bat.

On June 15, 1997, in one of the very first instances of regular-season interleague play, the Los Angeles Dodgers chose to send Nelson Liriano, a second baseman, up to pinch-hit for catcher Tom Prince in the eighth inning of their game against the Seattle Mariners. In the bottom half, Mike Piazza, who had started the game at DH, took the field as a catcher. Prince's original spot in the batting order came up again in the ninth inning, requiring the Dodgers either to have reliever Antonio Osuna swing the bat or turn to a pinch-hitter. Outfielder Eric Anthony pinch-hit, and popped out to end the game.

On October 1, 2000, the Detroit Tigers willingly surrendered the DH position late in a game against the Minnesota Twins.[41][42] With the Tigers and Twins out of playoff contention, Tigers manager Phil Garner decided beforehand that utility playerShane Halter would play all nine defensive positions.[41][43] Halter began the game batting 8th and playing first base. At the start of the 8th inning, Halter moved to pitcher. In a series of corresponding defensive changes, Bobby Higginson moved from DH to left field and the Tigers lost the DH. After Halter walked the only batter he faced (Matt LeCroy), he moved to second base, Brad Ausmus moved from second base to first base, and first basemen Robert Fick moved to pitcher, where he was immediately replaced by relief pitcher Matt Anderson, who would bat ninth. Anderson was replaced by closer Todd Jones for the top of the ninth inning. When Jones' spot in the order came up in the bottom of the ninth, he was pinch hit for by Billy McMillon, who singled. The next hitter, Hal Morris, singled in the game-winning run, scoring Halter.[42] The Tigers, using 15 position players and making use of expanded rosters, won 12–11 on the final game of the season. The Tigers and Twins tied an American League record for total players used with 42.[43]

There have been times when a manager may willingly surrender the DH position late in a game. During the 2005 American League Division Series between the New York Yankees and the Los Angeles Angels of Anaheim, New York had Bernie Williams slated as the designated hitter.[44] Late in the game, manager Joe Torre took Williams out of the DH and put him in center field because of Williams' superior defensive play. Since the Yankees already had the lead, not giving up any more runs was more important to Torre than having a better hitter hit for the pitcher in the game at the time, Yankees closer Mariano Rivera. Because a double switch was used, it was not necessarily a negative situation to have Rivera bat. Rivera's place in the order would have only come up if the Yankees batted around, which would have inherently meant their lead would have been further increased at that late point in the game anyway, giving more cushion for the Yankees' best relief pitcher to close out the game.

On May 28, 2009, Minnesota Twins catcher Mike Redmond was ejected from a game in Minneapolis against the Boston Red Sox after disputing umpire Todd Tichenor's call on a close play at home plate. Because Minnesota's normal starting catcher Joe Mauer was in the game as the DH and no other catcher was available, Minnesota was forced to forfeit the DH position for the remainder of the game. The pitcher was replaced with a pinch hitter both times it came up in Boston's 3–1 victory.[45]

On October 19, 2009, in the ALCS Game 3 New York Yankees designated hitter Jerry Hairston replaced left fielder Johnny Damon in the outfield in the 10th inning. This move forfeited their designated hitter and made the pitcher spot come up third in the 11th inning.

On September 13, 2010, Tampa Bay Rays catcher Kelly Shoppach was replaced by pinch-runner Desmond Jennings after Shoppach was hit by a pitch in the bottom of the 8th in a tight pitchers duel between the Rays' David Price and the Yankees' CC Sabathia. Dioner Navarro moved from designated hitter to catcher to start the 9th inning, thereby sacrificing Tampa Bay's designated hitter. By the time the DH spot was due up to bat in the 10th inning, pitcher Joaquín Benoit was pinch-hit for by Dan Johnson, who singled to right field.

On July 30, 2011, in the 2nd game of a double-header against the Baltimore Orioles, New York Yankees DH Nick Swisher was switched over to his traditional right field position in the top of the 8th inning, while starting pitcher Iván Nova was replaced by Luis Ayala. While the Yankees forfeited their right to a DH in the process, the 8th inning ended before Ayala would have come up to bat, and as the Yankees were the home team and leading, the bottom of the 9th inning was not played.[47]

On August 15, 2012, in a game against the New York Yankees, Texas Rangers 2nd baseman Ian Kinsler was ejected in the 8th inning for arguing a called strike three. With no one on the bench, designated hitter Michael Young took over at 2nd base, placing pitcher Mike Adams in Kinsler's spot in the batting order. The game ended before that spot in the lineup was reached again.

On June 29, 2013, in a game against the Chicago Cubs, the Seattle Mariners' center fielder Dustin Ackley left the game with an injury in the ninth inning. The only outfielder left on their bench was Michael Saunders, who had himself sustained a minor injury in the prior day's game. For that reason, the Mariners sent their DH Jason Bay into the field, and the pitcher's spot came up in the bottom of the ninth. Only backup catcher Henry Blanco remained as a possible pinch-hitter. He came into the game and drew a walk. Saunders was able to run, but not field nor swing a bat, so he pinch-ran for Blanco and scored the tying run. The game went into extra innings, and the pitcher's spot came up in the bottom of the 11th. Reliever Óliver Pérez was the pitcher of record at the time for the Mariners, but Joe Saunders (normally a starting pitcher) pinch-hit for him. He flew out to end the game.

On June 15, 2014, in the bottom of the eighth inning of a game against the Texas Rangers, Seattle Mariners first baseman John Buck was removed from the game for pinch runner Cole Gillespie. At the beginning of the ninth inning, Gillespie was removed and second baseman Willie Bloomquist moved to first. Designated hitter Robinson Cano took the field at second base. Relief pitcher Charlie Furbush thus entered the lineup at Buck and Gillespie's previous slot. Furbush would have been due to bat third in the bottom of the ninth, but the Mariners did not bat in the ninth as they led halfway through the inning.[49]

Pitcher Mark Langston pinch-ran for designated hitter Hubie Brooks in the top of the 9th inning, scored on a single, and then was in the remainder of the extra-inning game as the DH finishing with two strikeouts in a game at the Chicago White Sox on June 10, 1992.[51]

The 1976 World Series was the first time the designated hitter was used in a National League park; from 1976 through 1984, during even-numbered years, the designated hitter was used the entire series regardless of venue. Beginning in 1986, the league rules of the home team for each game would be the determining factor for that game.

April 10, 2007 was the second time the designated hitter was used at a National League park during a regular-season game. The Cleveland Indians, having already had their home-opening series against the Seattle Mariners postponed in its entirety because of a major winter storm, and the three games rescheduled for later in the season, and facing the same prospect in their next series against the Anaheim Angels, were forced to move those games to Milwaukee. This was the first time American League rules were used in Milwaukee since 1997 and the first time at Miller Park.

In June 2010 an interleague series between the Philadelphia Phillies and the Toronto Blue Jays scheduled to be played in Toronto was moved to Philadelphia due to the G-20 summit in Toronto. The Blue Jays batted as the home team, and the designated hitter was used in a National League ballpark for the third time in MLB history.

In June 2011 due to a previously scheduled U2 concert at Sun Life Stadium, an interleague series between the Florida Marlins and Seattle Mariners was moved to Safeco Field, home of the Seattle Mariners. Since the series was originally going to take place in a National League stadium, National League rules were used with no DH. The Marlins thus were the home team. Mariners pitcher Felix Hernandez hit a single.[59]

The rationale for the designated hitter rule arose comparatively early in the history of professional baseball. It was observed that, with a few exceptions — most notably Babe Ruth, who began his career as a pitcher with the Boston Red Sox — pitchers are usually selected for the quality of their pitching, not their hitting, and that most pitchers were weak hitters who had to be batted ninth in the batting order and pinch-hit for late in games when their team was trailing. The designated hitter idea was raised by Philadelphia Athletics manager Connie Mack in 1906,[60] though he was not the first to propose it. The rumors were that he grew weary of watching Eddie Plank and Charles Bender flail at pitches when at bat. Mack's proposal received little support and was even lambasted by the press as "wrong theoretically". The notion did not die. In the late 1920s, National League president John Heydler made a number of attempts to introduce a 10th man designated hitter as a way to speed up the game, and almost convinced National League clubs to agree to try it during spring training in 1929.[60]

However, momentum to implement the DH did not pick up until the pitching dominance of the late 1960s. In 1968, Denny McLain won 31 games and Bob Gibson had a 1.12 ERA, while Carl Yastrzemski led the American League in hitting with a .301 average. After the season, the rules were changed to lower the mound from 15 to 10 inches and change the upper limit of the strike zone from the top of a batter's shoulders to his armpits. In addition, in 1969 spring training, both the American League and National League agreed to try the designated pinch hitter (DPH), but they did not agree on the implementation. Most NL teams chose not to participate. On March 6, 1969, two games utilized the new DPH rule for the very first time. Two newly formed expansion teams, the Montreal Expos and the Kansas City Royals, would participate in one such game, and the New York Yankees and Washington Senators in the other. On March 26, 1969, Major League Baseball nixed the idea for the time being. Like other experimental baseball rule changes of the 1960s and '70s, the DH was embraced by Oakland A's owner Charlie O. Finley. On January 11, 1973, Finley and the other American League owners voted 8–4 to approve the designated hitter for a three-year trial run.[60]

On April 6, 1973, Ron Blomberg of the New York Yankees became the first designated hitter in Major League Baseball history, facing Boston Red Sox right-handed pitcher Luis Tiant in his first plate appearance. "Boomer" Blomberg was walked.[61]

As would be expected, the result of the first season of the DH was that the American League posted a higher batting average than the National League, something which has remained consistent to this day.

In response to increases in American League attendance because of the designated hitter, the National League held a yes/no vote on August 13, 1980 to determine whether or not the league would adopt the designated hitter. A simple majority of the 12 member teams was necessary to pass the rule, and the measure was expected to pass. However, when the teams were informed that the rule would not come into effect until the 1982 season, Philadelphia Phillies Vice President, Bill Giles, was unsure of how the team owner, Ruly Carpenter, wanted him to vote. Unable to contact Carpenter, who was on a fishing trip, Giles was forced to abstain from voting. Prior to the meeting, Harding Peterson, general manager for the Pittsburgh Pirates, was told to side with the Phillies. The final tally was four teams voting for the DH (Atlanta Braves, New York Mets, St. Louis Cardinals, and San Diego Padres), five votes against (Chicago Cubs, Cincinnati Reds, Los Angeles Dodgers, Montreal Expos, and San Francisco Giants), and three abstentions (Philadelphia Phillies, Pittsburgh Pirates, and Houston Astros). Five days after that meeting, the Cardinals fired their general manager, John Clairborne, who was the leading proponent for the adoption of the DH rule, and the National League has not held another vote on the issue ever since.[62]

As time passed, the designated hitter rule has ended up offering American League managers multiple strategic options in setting their teams' lineups: they can rotate the DH role among part-time players (for example, using a left-handed batter against a right-handed pitcher and vice versa) or they can employ a full-time designated hitter against all pitchers. It also allows them to give a healthy everyday player a partial day off, or to give an injured player the opportunity to bat without exposing him to re-injury while playing in the field.

In recent years, full-time DHs have become less common, and the position has been used to give players a partial off-day, allowing them to bat but rest while the other team is batting. This option comes in very handy when a team's lineup includes several older players. The 2012 Yankees, for example, rotated five players through the DH spot during the season, all of them over thirty-four years old.[63] Only a handful of players compile over 400 at-bats as a DH each year.

With the Houston Astros having moved to the American League for the 2013 MLB season, which requires interleague play season-round (as well as the Astros to start using a DH full-time), there is debate within MLB to unify the rules of the two leagues, with either the American League returning to its pre-1973 rules and have the pitcher hit, like the National League or the National League adopting the DH.[64]

Major League Baseball presents an annual award to the most outstanding designated hitter of the season, called the Edgar Martínez Award. Renamed for the former Seattle Mariners DH after his retirement in 2004, the Outstanding DH Award was introduced in 1973 and has been handed out every season since, except 1994 due to a player's strike. Notable winners include Martínez (five times) and David Ortiz (seven times, five consecutively).

DHs have generally not made much impact on the Major League Baseball Most Valuable Player Award or Major League Baseball Hall of Fame voting, because of the relative rareness of the full-time DH and the fact that the DH does not contribute on defense. During the 2009 season Hideki Matsui became the first player to win the World Series Most Valuable Player award while playing 116 of 147 games (78.9%) as a designated hitter. Among Hall of Famers, Paul Molitor and Jim Rice were, until 2014, the only inductees to even have played 25% of their games at DH. With the election of Frank Thomas on January 8, 2014, he becomes the first Hall of Famer to play the majority of his games at DH. Edgar Martínez is currently on the ballot, but his percentage of votes has dropped from 36.5% in 2012 and 35.9% in 2013 to just 25.2% in 2014. He does, however, remain eligible.

There is considerable debate over whether or not the designated hitter rule should be removed.[65][66] Some [65] have argued that the National League should adopt it. On the other hand, there are also fans who enjoy the fact that the American and National Leagues use different rules. Two generations of fans of American League teams have grown up with the designated hitter rule being in place, so some may consider the designated hitter to be as much a traditional part of baseball as the pitcher taking his turn at bat is for fans of National League teams.

Critics often argue that use of the designated hitter introduces an asymmetry to the game by separating players into classes, creating offensive and defensive specialization more akin to American football. Opponents of the rule believe it effectively separates pitchers, other fielders, and designated hitters into separate roles that never cross, possibly causing issues with promoting 'batting cage' players whose scope of experience is extremely limited. However, when the pitcher bats alongside everyone else, all nine players must take turns at the plate and in the field, and the hybridization of roles requires that everyone knows other roles in addition to their own.

The designated hitter rule also changes managerial strategy in late innings. In the National League, a manager must decide when to let a pitcher bat or remove him, as well as whom to pinch-hit with and where or if that player should take the field afterward. When the decision to remove a pitcher is made, the manager may also elect to double switch, delaying the new pitcher's turn at bat.

Advocates of the designated hitter [65][66] point to the fact that it has extended many careers, and, in a few cases, created long, productive careers for players who are weak fielders or have a history of injuries, such as Edgar Martínez and David Ortiz. Hall of Fame members George Brett, Carl Yastrzemski, and Paul Molitor continued their careers longer than they ordinarily would have without the rule.[67]Barry Bonds, who spent his entire career in the National League and actually won eight Gold Gloves earlier in his career, was used strictly as a DH later in his career when the San Francisco Giants played away interleague games due to his poor fielding.[68] Some believe that extending careers of older players is less of an advantage and more of a disadvantage, filling spots that otherwise may have been taken by younger players who end up not finding a place in the major leagues.

Interleague play has added a new wrinkle to the controversy. Some feel that it is not fair to ask an AL team to play without their DH when their roster has not been set up to do so, or on the other hand, to ask an NL team to use a DH when they may not have an appropriate player. Major League Baseball CommissionerBud Selig once proposed that the road team's rules should be followed for interleague games in order to combat this advantage for the home team, but the idea has not received traction.[69]

The decline of pitcher Chien-Ming Wang due to an interleague game injury has been cited in support of the designated hitter. On June 15, 2008, Wang was taken out of an interleague game versus the Houston Astros due to a right foot injury he sustained while running the bases, something he was not used to doing, since pitchers do not bat in the American League. Wang was diagnosed with a torn Lisfranc ligament and a partial tear of the peroneus longus of the right foot. The cast was removed on July 29, but the extensive rehabilitation process prevented Wang from being an effective pitcher at the major league level since. Yankees' part-owner Hank Steinbrenner showed frustration with pitchers having to bat in the National League and suggested that the League "join the modern age".[70]

Among minor league baseball teams, Rookie and Single-A level leagues use the DH in all games. At the Double-A and Triple-A level, when both teams are National League affiliates, pitchers may bat. In the Pacific Coast League, pitchers only hit when both clubs are NL affiliates and both clubs agree to have their pitchers hit. The reason for the difference is that as players get closer to reaching the majors, teams prefer to have the rules mimic, as closely as possible, those of the major league teams for which the players may soon be playing.[71]

The DH is used in most professional baseball leagues around the world. One notable exception is the Central League of Japan, where pitchers bat as they do in the National League. Japan's Pacific League adopted the designated hitter in 1975. When teams from different leagues play against each other in the Japan Series or interleague games, the DH rule is adopted if the Pacific League's team hosts the game. The DH rule is used in the Japanese minor leagues.

The use of the designated hitter rule in amateur baseball is nearly universal. The primary difference between the DH in the professional and amateur games is that the DH may bat in place of one player in any position in most amateur baseball leagues such as those that use National Federation of State High School Associations (NFHS) rules. Most high school coaches use a designated hitter in place of the weakest hitter in the lineup, if they use one at all. In amateur baseball, many pitchers are also good hitters and will often play another position (or even DH) when not pitching. Professional pitchers usually focus exclusively on improving their pitching, thus their batting skills often deteriorate compared to their teammates. However, in Canada, the DH must bat for the pitcher still.

One notable exception to the NFHS designated hitter rule in youth baseball is American Legion baseball. Legion rules exactly follow those prescribed in the Official Baseball Rules, which allow the DH only to bat for the pitcher. Prior to 1995, the use of the DH was not allowed in Legion baseball. Japanese high school baseball is one of the few amateur baseball leagues in the world that has never used the designated hitter rule at all. In high school baseball in South Korea, the rule has been adopted since 2004.

In college baseball, NCAA rules state that the designated hitter must hit for the pitcher, but in many instances the pitcher is also a good hitter, and the coach may elect to let the pitcher bat in the lineup. If the pitcher opts to bat for himself, he is treated as two separate positions — a pitcher and a designated hitter (abbreviated P/DH on the lineup card) — and may be substituted for as such (i.e. if he is removed as the pitcher, he may remain as the designated hitter and vice versa). However, if a player who starts a game as a P/DH is relieved as the starting pitcher, he may not return to the mound even if he remains in the game as the DH, and he may not play any other defensive position after being relieved as the pitcher. Conversely, a player who begins the game as the DH, but not as the pitcher, may come into the game as a reliever and remain as the DH (in effect becoming a P/DH), be relieved on the mound later in the game but continue to bat as the DH.

In Little League Baseball, the DH is not used. However, a league may adopt a rule which requires all players present and able to play to be listed in the batting order (such that the order contains more than nine players), and thus all players will have a turn to bat even when they are not assigned a fielding position.

^ abcWulf, Steve (1993-04-05). "Distinguished History". Sports Illustrated. Retrieved 2008-03-31. The following excerpt is from the article "Why the Pitcher Ought to Bat", which first appeared in the Philadelphia North American and was reprinted in the Feb. 3, 1906, edition of Sporting Life: The suggestion, often made, that the pitcher be denied a chance to bat, and a substitute player sent up to hit every time, has been brought to life again, and will come up for consideration when the American and National League Committees on rules get together. This time Connie Mack is credited with having made the suggestion.

Chen, Albert (April 11, 2011). "Going, Going ... Gone?: Adam Dunn is powerful, plodding, productive and very well paid—and in today's game, he's a dinosaur. In an era that values run prevention and lineup flexibility, the DH as we knew it is a dying breed". Sports Illustrated. p. 53.